The Big Idea Many important practical and mathematical applications involve comparing quantities of one kind or another; it is important to know which method to use and how we should use them.
Notes: A T-Rex weighed 8100 kilograms and was about 6 meters tall. The size of its skull is about 1 meter long and had 15-centimeter long incisors. A “larger than average human being weighs 90 kilograms and is 2 meters tall. A human’s skull is about 20 centimeters long and has incisors 1 centimeter long.
Problem 6.1: Scaling Up or Down
Write a paragraph to help someone younger than you understand how the size of the T-Rex compares to the size of a human. Be very specific about the comparisons you are making.
The T-Rex was one of the most fascinating creatures that weighed a massive 8100 kilograms. A human weighs about 90 kilograms, which means a T-Rex weighs 90 times more. A T-Rex was 6 meters tall while a human is only 2 meters tall. So if you put 3 humans on top of one another, they will be as tall as the T-Rex. It takes 5 human skulls to be as long as a T-Rex skull because a human skull is 20 centimeters long while a T-Rex’s is a full meter. You may think 15 centimeters is not very long, but for a tooth, it’s huge! If a human tooth is just 1 centimeter, just imagine how big the T-Rex’s 15-centimeter tooth is. That means its tooth is exactly 15 times longer. That’s how big the T-Rex was compared to a large human.
Problem 6.1 Follow-Up
1.Suppose an infant T-Rex was the same height as the human described in this problem and was similar to an adult T-Rex. What would be the scale factor between a grown T-Rex and an infant T-Rex?
If an infant T-Rex is the same height as a large human, it’s 2 meters tall. The scale factor between the adult and infant is 1/3.
2.How long were the incisors of this young T-Rex?
Grown T-Rex’s incisors= 15cm
Scale Factor=1/3
1/3 of 15cm=5cm
So the length of the infant’s incisors is 5cm
3.How long was the skull of this young T-Rex?
Grown T-Rex’s skull=1 meter
Scale Factor=1/3
1/3 of a meter=33cm
So the length of the infant’s skull is 33 cm
Ajwad Khan
Jan. 14, 10
Math 7B
The Big Idea Many important practical and mathematical applications involve comparing quantities of one kind or another; it is important to know which method to use and how we should use them.
Notes: A T-Rex weighed 8100 kilograms and was about 6 meters tall. The size of its skull is about 1 meter long and had 15-centimeter long incisors. A “larger than average human being weighs 90 kilograms and is 2 meters tall. A human’s skull is about 20 centimeters long and has incisors 1 centimeter long.Problem 6.1: Scaling Up or Down
Write a paragraph to help someone younger than you understand how the size of the T-Rex compares to the size of a human. Be very specific about the comparisons you are making.
The T-Rex was one of the most fascinating creatures that weighed a massive 8100 kilograms. A human weighs about 90 kilograms, which means a T-Rex weighs 90 times more. A T-Rex was 6 meters tall while a human is only 2 meters tall. So if you put 3 humans on top of one another, they will be as tall as the T-Rex. It takes 5 human skulls to be as long as a T-Rex skull because a human skull is 20 centimeters long while a T-Rex’s is a full meter. You may think 15 centimeters is not very long, but for a tooth, it’s huge! If a human tooth is just 1 centimeter, just imagine how big the T-Rex’s 15-centimeter tooth is. That means its tooth is exactly 15 times longer. That’s how big the T-Rex was compared to a large human.
Problem 6.1 Follow-Up
1. Suppose an infant T-Rex was the same height as the human described in this problem and was similar to an adult T-Rex. What would be the scale factor between a grown T-Rex and an infant T-Rex?
If an infant T-Rex is the same height as a large human, it’s 2 meters tall. The scale factor between the adult and infant is 1/3.
2. How long were the incisors of this young T-Rex?
Grown T-Rex’s incisors= 15cm
Scale Factor=1/3
1/3 of 15cm=5cm
So the length of the infant’s incisors is 5cm
3. How long was the skull of this young T-Rex?
Grown T-Rex’s skull=1 meter
Scale Factor=1/3
1/3 of a meter=33cm
So the length of the infant’s skull is 33 cm